cross fingers I guess?

Some dispensaries don't ask for proof of mailing. If they do, tell them what happened or just go to another one. It's not like there is about 300 in the Denver area to check out. I would imagine there's a couple who don't care as long as you have a Doc's recommendation. Technically that's all thats required, it's voluntary to register with the State. I know guys who just have a letter from their Dr and it's what they carry around with them. Of course they don't visit many dispensaries so not sure how they works for them at those places.